Photographic developer composition



Patented Aug. 3, 1954 UNITED STATES PATENT OFFICE PHOTOGRAPHIC DEVELOPER COMPOSITION No Drawing. Application August 3, 1953,

Serial No. 372,191

15 Claims.

This invention relates to photographic developers and particularly to methods for accelerdihydropyrogallol Coumarindlol O OH OH i l,2,3-trlhydroxynaphthalene (keto form) 'lhlacoumarlndiol m-zi i- Carbostyrlldlol HaC- OH HaC- fi-methylthiacoumarindiol OH O I II OH I N-methylcarbostyrlldiol 2. These ene-diol compounds, exceptfor dihydropyrogallol, have the following general formula wherein R represents a substituent such as an akyl group preferably containing from 1 to- 4- carbon atoms e. g. methyl, ethyl, n-propyl and nbutyl, an alkoxy group e. g. methoxy, or a halogen atom e. g; chlorine and bromine, and Z represents either a sulfur or oxygen atom, or a methylene group, imino group or the N-alkyl group.=NR1 in which R1 preferably contains from 1 to 4 carbon atoms e. g. a N-methyl, N-ethyl, N-n-propyl or N-n-butyl group. The equilibrium forms of these compounds, such as those shown hereinabove, are contemplated in the developers of our invention.

It. is considered that the active portion of the molecule is that containing the cyclic ene-diol system. The compounds are not to be confused with polyhydric aromatic compounds such as catechol orpyrogallol which show serious disadvantages such as a strong tendency to form colored oxidation products in the development reaction or on contact with the oxygen in the air, which products discolor solutions and stain photographic materials.

We have discovered that the developing rate of developing solutions containing the above ene-diol compounds can be markedly accelerated by the addition to developing solutions containing the ene-diol compounds, of '3-pyrazolidone compounds which themselves are only moderately active developing agents for silver halide. The activity of the resulting developer solution containing. both the ene-diol and pyrazolidone compounds is very much greater than would be expected from summing up the separate activities. An added feature of the ene-diol-pyrazolidone developer compositions resides in the stability of the developing solution; that is, S-pyrazoliclone compounds such as l-phenyl-B-pyrazoliclone are highly unstable in alkaline developer compositions free of a preservative and tend to darken and lose development activity quickly particularly through aerial oxidation. On the other hand, when development is carried out with the 3-pyrazolidone compounds in the presence of the ene-diol compounds, the latter function as me servatives and the developer is highly resistant to discoloration and loss of activity. Another advantageous characteristic of the ene-diol-pyraz olidone developercompositions is that the de-' 6- velopers show little tendency for the formation of silver sludge or for the formation of dichroic stain on silver images. A further characteristic of the ene-diol-pyrazolidone developer compositions of the invention resides in the fact that the compositions behave as strong surface latent image developers as opposed to internal latent image developers, as long as they are free of silver halide solvents such as sodium sulfite. That is, developer compositions containing 3-pyrazolidone compounds have been described in the literature but invariably they have been compounded so as to contain a silver halide solvent such as sodium sulfite as a preservative. In order to convert such a developer composition to a surface latent image developer we have found it to be necessary to dispense with the silver halide solvent in the developer composition. However, as mentioned, the 3-pyrazolidone developers free of preservative are very unstable. When, according to our invention, the ene-diol compounds are incorporated into the S-pyrazolidone developer compositions, the ene-diol compounds supply the required preservative effect and the surface latent image developer characteristics are maintained. Therefore, the fortuitous choice of B-pyrazolidone compounds to accelerate the development rate of the ene-diol compounds has resulted in the latter compounds exerting a complementary preservative effect as well as providing a stable 3-pyrazolidone developer system which has surface latent image development characteristics and shows no tendency for physical development. For these reasons the developers of the invention are very useful in color development processes where a black and white developer is required.

An additional unexpected feature of the developers containing the 3-pyrazolidone and enediol compounds resides in the fact that similar developer compositions can be prepared in which the pyrazolidone is replaced by a conventional developing agent, for example, containing a mixture of N-methyl-p-aminophenol and dihydropyrogallol, which compositions do not exhibit the mentioned development acceleration effect to anything like the same degree.

The 3-pyrazolidone developer compositions of the invention containing the above ene-diol compounds can be readily converted to internal latent image developer compositions by merely adding a silver halide solvent such as sodium thiosulfate thereto. The resultant internal latentimage developer composition, by virtue of the presence of one of the mentioned ene-diol compounds, possesses satisfactory keeping properties even in the absence of the usual sulfite preservative.

The 3-pyrazolidone silver halide developing agents employed in the developer compositions together with the ene-diols, have the general structure in which the R. groups each represent various substituents such as hydrogen, alkyl or aryl groups, for example B1 can be hydrogen or a group such as alkyl preferably containing from 1 to 4 carbon atoms, or an aryl group of the benzene or naphthalene series substituted or not, and R2, R3, R4 and Re can be hydrogen atoms or alkyl as above or aryl such as phenyl.

The following compounds are representative of B-pyrazolldone silver halide developing agents which are useful in the developer compositions of the invention:

1. 1-phenyl-3-pyrazolidone 2. 1-p-tolyl-3-pyrazolidone 3. 5-phenyl-3-pyrazolidone 4. 5-methyl-3-pyrazolidone 5. 1-p-chlorophenyl-3-pyrazolidone 6. l-phenyl-fi-phenyl-Ii-pyrazolidone 7. 1-m-tolyl-3-pyrazolidone 8. 1-phenyl-5-methyl-3-pyrazolidone 9. 1-p-tolyl-5-phenyl-3-pyrazolidone 10. l-m-tolyl-3-pyrazolidone l l. 1 -p -methoxyphenyl-3 -pyrazolidone 12. l-acetamidophenyl3-pyrazolidone 13. l-phenyl-2-acetyl 4,4= dimethyl 3 pyrazolidone 14. 1-phenyl-4,l-dimethyl-3-pyrazolidone 15. 1-m-aminophenyl- 4 methyl 4 propyl-3- pyrazolidone 16. l-o chlorophenyl 4 methyl 4 ethyl 3- pyrazolidone 1'7. 1 m acetamidophenyl 4,4 diethyl 3- pyrazolidone The 4,4-dialkyl-3-pyrazolidone compounds 13 to 23 and 26 above are particularly efiicacious for use in the developer compositions of our invention inasmuch as they are more active developing agents than are compounds 1 to 12 which contain a single substituent or only hydrogen atoms in the 4-position of the pyrazolidone nucleus. The 4A-dialkyl-3-pyrazolidone compounds are described and claimed in the Allen et al. U. S. patent application Serial No. 372,148 filed concurrently herewith. The w-hydroxy-alkylphenyl-3 pyrazolidones, for example, compounds 18 and 24 above, are also especially useful in concentrated formulas, in replenishers and in the presence of high salt concentrations where their increased solubility enables obtaining and holding adequate amounts of the pyrazolidone compound in solution. The compounds are described and claimed in the Allen et al. U. S. patent application Serial No. 372,148 filed concurrently herewith and in the Reynolds and, Tinker U. S. patent application Serial No. 372,167 filed concurrently.

Example 1 A developer or the following composition was prepared:

The solution was used to develop a fine-grain positive film, a density of 0.95 being obtained after 2 minutes development. The same solution containing only dihydropyrogallol as the developing agent required 32 minutes to develop a density of 0.31 and when the solution contained only 1-phenyl-3-pyrazolidone as the developing agent, the film developed to a density of only 0.30 in 2 minutes.

Example 2 The following developer composition is suitable for use as a negative developer for color films:

Water to make 1.0 liter.

The developer of this example can be used in any of the well-known processes of color development where a black-and-white developer is required. The developer is especially useful in mixed grain color processes employing films such as disclosed in Mannes et al. U. S. Patent 2,388,856 or in the Carroll et a1. U. S. Patent 2,614,925, October 21, 1952, wherein, for example, is shown a two-layer film, one layer containing blue-sensitive silver halide, the other containing a mixture of green and red-sensitive silver halide grains. When the developer immediately above is used, particularly if the formula is free of sulfite, in the color process of the patents as the negative developer for such a film it is observed that physical development efiects are minimized with the result that the color developed images have increased saturation because of decreased physical development in the negative developer of the invention.

Results similar to those shown in the above examples are obtained when the developer compositions either containing or free of silver halide solvents are prepared from mixtures of at least one of the indicated 3-pyrazolidone compounds and at least one of the indicated ene-diol compounds. Particularly valuable developer compositions in addition to that exemplified above are those containing dihydropyrogallol and either a 1-toly1-3-pyrazo1idone such as 1-p-tolyl-3- pyrazolidone or 1 p tolyl 4,4 dimethyl 3- pyrazolidone or a 1-(p-hydroxyalkylphenyl) -4,4- dialkyl-3-pyrazolidone such as l-(p-fl-hydroethylphenyl)-4,4=-dimethyl-3-pyrazolidone, or a 1 (p hydroxyalkylphenyl) 3 pyrazolidone such as 1 (p ,8 hydroxyethylphenyl) 3- pyrazolidone.

It will be understood that our invention, as specified by the claim hereinafter, includes the mentioned developer compositions in either the liquid form exemplified above, or in the dry powder form such as packaged developer formulas suitable for dissolving in water to form a liquid developer. Such dry compositions include the mentioned 3-pyrazolidone compounds, the enediol compound, and alkaline material such as sodium carbonate, caustic alkali or sodium perborate.

What I claim is:

1. A photographic developer composition comprising an alkaline material, a 3-pyrazolidone silver halide developing agent and a member of 6 the group consisting of compounds having the general formula wherein R represents a member of the group consisting of an alkyl group of from 1 to 4 carbon atoms, an alkoxyl group of from 1 to 4 carbon atoms and a halogen atom, and Z represents a member of the group consisting of an N-alkyl group of from 1 to 4 carbon atoms, a methylene group, an imino group, a sulfur atom and an oxygen atom, and dihydropyrogallol.

2. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a B-pyrazolidone silver halide developing agent and a compound selected from the group consisting of a coumarindiol; a thiacoumarindiol; a carbostyrildiol; a 1,2,3-trihydroxynaphthalene; and dihydropyrogallol.

3. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a 3-pyrazo1idone silver halide developing agent and coumarindiol.

4. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a 3-pyrazolidone silver halide developing agent and thiacoumarindiol.

5. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a 3-pyrazolidone silver halide developing agent and carbostyrildiol.

6. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a B-pyrazolidone silver halide developing agent and dihydropyrogallol.

7. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a 3-pyrazolidone silver halide developing agent and 1,2,3-trihydroxynaphthalene.

8. The developer composition of claim 1 containing l-phenyl-B-pyrazolidone as the 3-pyrazolidone silver halide developing agent.

9. The developer composition of claim 1 containing a l-tolyl-3-pyrazolidone as the 3-pyrazolidone silver halide developing agent.

10. The developer composition of claim 1 containing a 4,4-dialkyl-3-pyrazolidone as the 3- pyrazolidone silver halide developing agent.

11. The developer composition of claim 1 containing a 1-tolyl-4,4-dimethyl-3-pyrazolidone as the 3-pyrazolidone silver halide developing agent.

12. The developer composition of claim 1 containing 1-p-tolyl-4,4-dimethyl-3-pyrazolidone as the B-pyrazolidone silver halide developing agent.

13. The developer composition of claim 1 containing 1-p- (p-hydroxyethylphenyl) -3-pyrazolidone as the 3-pyrazolidone silver halide developing agent.

14. The developer composition of claim 1 containing 1 (p 5 hydroxyethylphenyl) 4,4 dimethyl-B-pyrazolidone as the 3-pyrazolidone silver halide developing agent.

15. A photographic developer composition comprising an aqueous alkaline solution of a mixture of 1-phenyl-3-pyrazolidone and dihydropyrogallol.

No references cited. 

1. A PHOTOGRAPHIC DEVELOPER COMPOSITION COMPRISING AN ALKALINE MATERIAL, A 3-PYRAZOLIDONE SILVER HALIDE DEVELOPING AGENT AND A MEMBER OF THE GROUP CONSISTING OF COMPOUNDS HAVING THE GENERAL FORMULA 